Was the way the third hokage died really worth dieing for? sure he took orochimaru's jutsu but to end like that not even knowing if the village would survive.
if you ask me it wasn't a good plan, maybe he was unprepared and surprised on the attack but he shouldn't have been all the signs and even orochimarus warning, his fighting was poor and should have been better. sure he was old but he should have had a bit stronger jutsu.